INFO: task syz.2.24:6066 blocked for more than 143 seconds. Not tainted 6.16.0-rc7-syzkaller-00086-g0d9cfc9b8cb1 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.24 state:D stack:27240 pid:6066 tgid:6058 ppid:5850 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x16fd/0x4cf0 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0x165/0x360 kernel/sched/core.c:6879 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:148 __flush_work+0x9b9/0xbc0 kernel/workqueue.c:4246 __cancel_work_sync+0xbe/0x110 kernel/workqueue.c:4366 hidp_session_remove+0x62/0x260 net/bluetooth/hidp/core.c:1169 l2cap_unregister_user+0x18e/0x1b0 net/bluetooth/l2cap_core.c:1734 hidp_connection_del+0xb0/0x170 net/bluetooth/hidp/core.c:1409 do_hidp_sock_ioctl net/bluetooth/hidp/sock.c:97 [inline] hidp_sock_ioctl+0x317/0x560 net/bluetooth/hidp/sock.c:128 sock_do_ioctl+0xdc/0x300 net/socket.c:1190 sock_ioctl+0x576/0x790 net/socket.c:1311 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fcd92f8e9a9 RSP: 002b:00007fcd93eab038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fcd931b6080 RCX: 00007fcd92f8e9a9 RDX: 0000200000000000 RSI: 00000000400448c9 RDI: 0000000000000008 RBP: 00007fcd93010d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fcd931b6080 R15: 00007ffddf93f298 INFO: task khidpd_16d05505:6067 blocked for more than 144 seconds. Not tainted 6.16.0-rc7-syzkaller-00086-g0d9cfc9b8cb1 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:khidpd_16d05505 state:D stack:29160 pid:6067 tgid:6067 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x16fd/0x4cf0 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0x165/0x360 kernel/sched/core.c:6879 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6936 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x724/0xe80 kernel/locking/mutex.c:747 l2cap_unregister_user+0x6a/0x1b0 net/bluetooth/l2cap_core.c:1728 hidp_session_thread+0x3c9/0x410 net/bluetooth/hidp/core.c:1304 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Showing all locks held in the system: 3 locks held by kworker/u8:1/13: #0: ffff88801a489148 ( (wq_completion)events_unbound ){+.+.}-{0:0} , at: process_one_work kernel/workqueue.c:3213 [inline] , at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321 #1: ffffc90000127bc0 ( (linkwatch_work).work ){+.+.}-{0:0} , at: process_one_work kernel/workqueue.c:3214 [inline] , at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321 #2: ffffffff8f51c208 ( rtnl_mutex ){+.+.}-{4:4} , at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 1 lock held by khungtaskd/31: #0: ffffffff8e13f0e0 ( rcu_read_lock ){....}-{1:3} , at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] , at: rcu_read_lock include/linux/rcupdate.h:841 [inline] , at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 2 locks held by getty/5611: #0: ffff88814ca290a0 ( &tty->ldisc_sem ){++++}-{0:0} , at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036c62f0 ( &ldata->atomic_read_lock ){+.+.}-{4:4} , at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 8 locks held by kworker/1:4/5915: 2 locks held by syz.2.24/6066: #0: ffff8880338880b8 ( &hdev->lock){+.+.}-{4:4}, at: l2cap_unregister_user+0x6a/0x1b0 net/bluetooth/l2cap_core.c:1728 #1: ffffffff8f6ad4d0 ( hidp_session_sem ){++++}-{4:4} , at: hidp_session_remove+0x2c/0x260 net/bluetooth/hidp/core.c:1165 1 lock held by khidpd_16d05505/6067: #0: ffff8880338880b8 ( &hdev->lock ){+.+.}-{4:4} , at: l2cap_unregister_user+0x6a/0x1b0 net/bluetooth/l2cap_core.c:1728 2 locks held by kworker/u8:24/7546: #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321 #1: ffff8880b8623f08 ( &per_cpu_ptr(group->pcpu, cpu)->seq ){-.-.}-{0:0} , at: psi_task_switch+0x39a/0x6d0 kernel/sched/psi.c:987 1 lock held by syz.3.597/8243: #0: ffff8880338880b8 ( &hdev->lock ){+.+.}-{4:4} , at: hci_get_conn_list+0x14b/0x740 net/bluetooth/hci_conn.c:2615 1 lock held by syz.0.1351/11049: #0: ffffffff8f51c208 ( rtnl_mutex ){+.+.}-{4:4} , at: tun_detach drivers/net/tun.c:633 [inline] , at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3396 2 locks held by dhcpcd/11056: #0: ffff88807de4d608 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline] (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: __sock_release net/socket.c:646 [inline] (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1391 #1: ffffffff8e144bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #1: ffffffff8e144bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:998 1 lock held by dhcpcd/11057: #0: ffff88807de49408 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline] #0: ffff88807de49408 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: __sock_release net/socket.c:646 [inline] #0: ffff88807de49408 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1391 2 locks held by dhcpcd/11058: #0: ffff888057635c08 ( &sb->s_type->i_mutex_key #11 ){+.+.}-{4:4} , at: inode_lock include/linux/fs.h:869 [inline] , at: __sock_release net/socket.c:646 [inline] , at: sock_close+0x9b/0x240 net/socket.c:1391 #1: ffffffff8e144bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] ffffffff8e144bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:998 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc7-syzkaller-00086-g0d9cfc9b8cb1 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:470 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5915 Comm: kworker/1:4 Not tainted 6.16.0-rc7-syzkaller-00086-g0d9cfc9b8cb1 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: events hidp_session_dev_work RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:409 Code: e8 2e f9 79 fc 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 0f 0b dc fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 8a 55 2a 06 cc 44 89 f9 80 e1 07 RSP: 0018:ffffc900044b6bf0 EFLAGS: 00000002 RAX: 1ffffffff33bec00 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020 RBP: ffffffff99df6590 R08: ffff8880242f8237 R09: 1ffff1100485f046 R10: dffffc0000000000 R11: ffffffff85462d50 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff99df6300 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125d23000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055a0ed06f168 CR3: 000000000df38000 CR4: 00000000003526f0 Call Trace: serial_in drivers/tty/serial/8250/8250.h:137 [inline] serial_lsr_in drivers/tty/serial/8250/8250.h:159 [inline] wait_for_lsr+0x1a1/0x2f0 drivers/tty/serial/8250/8250_port.c:2094 fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3348 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3371 [inline] serial8250_console_write+0x134c/0x1ba0 drivers/tty/serial/8250/8250_port.c:3456 console_emit_next_record kernel/printk/printk.c:3138 [inline] console_flush_all+0x725/0xc40 kernel/printk/printk.c:3226 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline] console_unlock+0xc4/0x270 kernel/printk/printk.c:3325 vprintk_emit+0x5b7/0x7a0 kernel/printk/printk.c:2450 dev_vprintk_emit+0x337/0x3f0 drivers/base/core.c:4917 dev_printk_emit+0xe0/0x130 drivers/base/core.c:4928 _dev_warn+0x10a/0x160 drivers/base/core.c:4984 hid_parser_main+0x8b8/0xc40 drivers/hid/hid-core.c:-1 hid_open_report+0x85b/0xee0 drivers/hid/hid-core.c:1328 hid_parse include/linux/hid.h:1133 [inline] hid_generic_probe+0x3d/0x90 drivers/hid/hid-generic.c:66 __hid_device_probe drivers/hid/hid-core.c:2733 [inline] hid_device_probe+0x3a0/0x710 drivers/hid/hid-core.c:2770 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x26d/0x9a0 drivers/base/dd.c:657 __driver_probe_device+0x18c/0x2f0 drivers/base/dd.c:799 driver_probe_device+0x4f/0x430 drivers/base/dd.c:829 __device_attach_driver+0x2ce/0x530 drivers/base/dd.c:957 bus_for_each_drv+0x24e/0x2e0 drivers/base/bus.c:462 __device_attach+0x2b8/0x400 drivers/base/dd.c:1029 bus_probe_device+0x185/0x260 drivers/base/bus.c:537 device_add+0x7b6/0xb50 drivers/base/core.c:3692 hid_add_device+0x398/0x540 drivers/hid/hid-core.c:2916 hidp_session_dev_add net/bluetooth/hidp/core.c:856 [inline] hidp_session_dev_work+0x45/0x160 net/bluetooth/hidp/core.c:895 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245